For an angel of God to describe Cornelius' prayers, for example, as a memorial before God, this means that God was truly impressed with the prayers Cornelius offered up to Him.  In Hebrews 5:7, it is written, " ⁷ In the days of his flesh, ^u Jesus² offered up prayers and supplications, ^v with loud cries and tears, to him ^w who was able to save him from death, and ^x he was heard because of his reverence. "  In order for God to hear our prayers, they must be offered up in reverence.

God says that if we ask wrongly, we will not receive what we ask for in prayer.  In 1 Kings 3:9-14, it is written, "' ^9 o Give your servant therefore an understanding mind ^p to govern your people, that I may ^q discern between good and evil, for who is able to govern this your great people? '  ¹⁰ It pleased the Lord that Solomon had asked this.  ¹¹ And God said to him, ' Because you have asked this, and have not asked for yourself long life or riches or the life of your enemies, but have asked for yourself understanding to discern what is right, ¹² behold, ^r I now do according to your word.  Behold, ^s I give you a wise and discerning mind, so that none like you has been before you and none like you shall arise after you.  ^13 t I give you also what you have not asked, ^u both riches and honor, so that no other king shall compare with you, all your days.  ¹⁴ And if you will walk in my ways, keeping my statutes and my commandments, ^v as your father David walked, then ^w I will lengthen your days. '"  When God is pleased with our prayers, He will give us more than we ask.  See also Ephesians, chapter 3 ( especially verse 20, for example ), for example.

When we ask to spend on our passions, then we are asking with selfish motives, and God will not give us what we ask for in that situation.  Unbelievers see no value in prayer, however, in 2 Corinthians 1:11, it is written, " ^11 s You also must help us by prayer, so that many will give thanks on our behalf ^t for the blessing granted us through the prayers of many " ( Emphasis mine, R.E.W. ).  Not only is prayer an opportunity to help others, but blessings are granted to those for whom we pray.

In Acts 12:5, it is written ( please read this entire chapter to get the immediate context ), " ⁵ So Peter was kept in prison, but earnest ^l prayer for him was made to God by the church. "  The church prayed for Peter, and he was miraculously released from prison.  May our prayers ascend as a memorial before God.